The PSNI has warned of a “very heavy build up of traffic” as emergency services attend the scene of a crash.
The crash took place at a busy roundabout near the Foyle Bridge in Londonderry.
A spokesperson for Foyle PSNI said: “There has been a collision between the Foyle Bridge and the Caw Roundabout on the Waterside bound side of the carriageway.
“This is causing a very heavy build up of traffic in the area which will not clear for some time whilst emergency services attend.”
The spokesperson added: “Please try to avoid the area if possible. We will update when the road is clear and appreciate your patience.”